Hire a Licensed Radon Pro

How to Hire a Licensed Radon Professional in Colorado

A radon system is a health-safety system that operates continuously for years. The fan, piping, collection zone, crawl-space membrane, discharge, electrical work, monitoring, and testing all have to function together. Colorado created a radon licensing program so consumers can verify who is legally responsible for professional measurement and mitigation.

The best contractor is not automatically the company with the lowest total, the largest advertisement, or the most national-certification logos. Start by verifying the Colorado license, then compare design, supervision, testing, warranty, and long-term service.

Request a Licensed Radon Quote Call 970-482-9100

Colorado licenses individual radon professionals. Ask for the name and license number of the person responsible for your testing or mitigation, then verify active status in the official DORA lookup.

Step 1: Confirm the Correct Colorado License

Radon Measurement Professional

Required for professional radon testing and measurement services. This license covers the measurement program, device and protocol oversight, quality control, and reporting.

Radon Mitigation Professional

Required for professional design, installation, repair, and modification of radon mitigation systems. This is the license to verify when hiring an installer or service contractor.

A company may employ both license types, but one does not automatically include the other. A national NRPP or NRSB certification supports professional qualification but does not replace the Colorado license. General contractor, plumbing, electrical, HVAC, roofing, home-inspection, or handyman credentials also do not replace it.

Step 2: Verify the License - Do Not Just Look at a Certificate

1
Find the responsible individual
Ask: Who is the Colorado-licensed person responsible for this job? What is the exact license number?
2
Search the DORA record
Use the official Colorado license lookup and confirm the license type, active status, expiration, and any available discipline information. Radon licenses expire annually on May 31 unless renewed.
3
Ask about the crew
If the people doing the field work are not individually licensed, ask how the licensed professional will provide the direct supervision required by Colorado law.
4
Save the verification
Keep a screenshot or PDF of the active license record with your proposal, report, warranty, and final test.

Step 3: Compare Written Scopes, Not Just Totals

Which foundation areas are included: basement slab, slab-on-grade, crawl space, addition, garage transition, or multiple zones?
How many suction points or collection zones are anticipated, and what assumptions could change that number?
What membrane material and sealing method will be used in the crawl space?
Where will the pipe, fan, electrical connection, alarm, monitoring device, and discharge be located?
Will the contractor test pressure-field extension or otherwise verify communication as appropriate?
Are permits, electrical work, roof or siding penetrations, cleanup, labels, and documentation included?
Is post-mitigation testing included, when will it occur, and who is responsible for measurement?
What happens if the initial post-test is still elevated?
What are the fan, installation, and performance warranty terms and exclusions?

Step 4: Look for These Quality Signals

The contractor explains the foundation

A reputable professional discusses slab divisions, crawl spaces, additions, soil-gas pathways, route options, and why the proposed fan and suction points fit the building.

The proposal is property-specific

It identifies the address, test result, included areas, route, major components, options, assumptions, warranty, and testing rather than providing only one line that says radon system.

The system can be serviced

The fan, monitoring device, alarm, electrical connection, crawl membrane, and critical fittings remain accessible and understandable to future owners.

The contractor discusses appearance and safety together

A clean route matters, but it should not create an unsafe fan location, a positive-pressure pipe through living space, a re-entry-prone discharge, or a roof detail that cannot be maintained.

The contractor provides post-installation proof

A final package should include operating instructions, labels, warranty, license information, system details, and a post-mitigation result.

The company remains available

Radon fans and systems require future testing and occasional service. Ask who will answer the phone if the alarm sounds or the fan fails years later.

Red Flags

No Colorado individual license number is provided
The salesperson says national certification is the same as a state license
A licensed person will sign later but will not supervise the field work
The contractor guarantees zero radon or says testing is unnecessary
The quote omits post-mitigation testing, monitoring, labels, or warranty terms
A crawl-space quote uses loose plastic with no detailed sealing or collection plan
The fan is proposed inside conditioned living space or the discharge is placed near an opening without explanation
The contractor recommends only sealing cracks as the complete solution
Payment is requested without a clear written scope, company identity, and change-order process

What About Do-It-Yourself Radon Work?

Colorado includes a limited exemption that allows an owner-occupant to measure or mitigate that person's own single-family residence. That is not an exemption for an unlicensed handyman, paid friend, seller, builder, property manager, or contractor. A person offering radon services to others still needs the applicable license or must work within a lawful supervised arrangement.

DIY work can also create electrical, condensate, roof, siding, firestopping, noise, crawl-space moisture, re-entry, and resale-documentation problems. Homeowners who choose DIY should still follow the applicable standard, obtain required trade permits, use approved devices, test afterward, and disclose the system accurately in a future sale.

Questions to Ask Every Radon Contractor

1What is the name and active Colorado license number of the responsible mitigation or measurement professional?
2Will that person be on site or directly supervising the work as Colorado requires?
3Which Colorado-incorporated standard applies to this building?
4How will you address each foundation zone and verify the system is drawing from the intended area?
5Where will the fan and discharge be, and why is that location compliant and serviceable?
6What post-mitigation test is included and what happens if the result is still elevated?
7What is covered by the fan, workmanship, and performance warranties?
8Are you insured at the level required for a Colorado radon mitigation or measurement professional?
9What permits, electrical work, and local inspections apply?
10Will I receive system documentation that can stay with the property?

Drennen Credentials and Consumer Protections

At the time this content was prepared, Drennen's radon program identified Colorado license RMT.0000022 for mitigation oversight and RME.0000045 for measurement oversight, together with national radon credentials. License status must always be verified directly with DORA before relying on it.

Drennen's current written warranty describes a 20-year installation-performance term tied to the completed post-mitigation result and a five-year manufacturer fan warranty, subject to the written exclusions and the homeowner's responsibility to retest at least every two years. Always review the current contract; website summaries do not replace it.

Frequently Asked Questions

Choose a Radon Company You Can Verify

Drennen will provide a written scope, identify the licensed program responsible for the work, explain the design, include post-mitigation testing for standard installations, and provide current warranty terms. We welcome informed comparisons.

Request a Licensed Radon Quote

Reviewed July 2026. This page is general consumer education. License status, rules, standards, local permits, and warranty terms can change. Verify current information directly with DORA, CDPHE, the local authority, and the written contract.

Drennen Custom Contracting | Serving Fort Collins and Northern Colorado | 970-482-9100 | [email protected]